The macromolecular substance comprises biomass, solid organic waste and industrial waste such as waste tires and the like, and belongs to a renewable energy substance. How to achieve high-efficiency clean conversion and utilization of the macromolecular substance has been a hot research subject of the science and technology workers around the world.
It is well known that energy utilization of the macromolecular substance at present comprises three modes as follows: 1, a traditional direct combustion utilization mode, which must be washed out because of low thermal efficiency and serious secondary pollution, 2, a liquefaction utilization mode, which still cannot be popularized at present because of large investment, high manufacturing cost, unstable quality, strict material requirements and absence of economical efficiency in comparison with fossil energy, 3, a gasification utilization mode, which comprises two aspects of biomass gasification burning and waste gasification incineration disposal, and is the most realistic and promising energy utilization mode at present. However, the secondary pollution problem of “tar” has not been effectively solved in the aspect of biomass gasification burning, resulting in slow progress of the biomass gasification utilization work in our country. For example, a biomass concentrated air supply device which has been widely promoted in the countryside in China and known as “making a fire by a person and cooking in the whole village”, kinds of technological means including high-temperature pyrolysis and catalytic cracking are adopted in treatment of a biomass tar, but the problem of tar pollution is still the main chief culprit of resulting in paralysis of the biomass concentrated air supply device in the end while “waste gasification incineration” is the inevitable course for finally achieving “harmless, recycling and reduction” treatment of the solid organic waste in the aspect of waste gasification incineration disposal, but highly toxic carcinogenic substances such as “dioxin” cannot be avoided in the prior art, so that it is difficult to carry out waste incineration disposal in various countries in the world. It's been shown that the respiratory cancer incidence of all residents around the places in which waste incineration plants are built is increased by about 70 times on the primary base in general, and “dioxin” pollution has become a public hazard of turning pale at the mention of a tiger in various countries in the world. Therefore, the plan of building 137 garbage furnaces had been forced to be concealed by the United States in 1985; 52 garbage furnaces in great lakes in North America were stopped in succession in 1996; the “garbage furnaces banning construction” was also issued by the European Union of Germany, Netherlands, Belgium and the like and Canada in succession. It is not uncommon to hear popular dissatisfaction caused by cancers due to “dioxin” pollution since the birth of the first waste incineration power plant in Guangzhou in August 2000. A project supposed to benefit the nation and the people became a focal point of generating popular discontent due to substandard prior art. In the face of rolling waste to be processed every day, governments at all levels actually enter a dilemma on whether building “waste incineration plants” or not. For eliminating “dioxin”, some waste incineration plants are forced to arrange the liquefied gas burning process and recycled circulation combustion process of partial tail gas at its tail gas processing section, which increases the equipment cost and improves the operating cost; and facts proved that the processing effect of the plants were not ideal. The inventor thinks that a common thought mistake mainly exists in the prior art as to “biomass gasification burning” or “waste gasification incineration disposal”, namely it is widely believed that the tar pollution problem can be fundamentally solved by as long as the tar macromolecular substances are completely cracked, and the existing biomass gas contains a certain amount of biomass tar due to incomplete tar cracking. For this reason, various tar cracking methods and cracking devices over the years are produced like the chambers, but the tar pollution problems produced during the biomass gasification burning process and the “dioxin” pollution problems produced during waste incineration process still exist, and those problems are not effectively solved. Actually, whatever the “catalytic cracking” or the “high-temperature pyrolysis” or the “nuclear magnetic resonance technology”, or whether the tar is completely cracked, not all the “micromolecular substances” produced by cracking the tar macromolecular substances are the micromolecular substances in the stable state, a part of tar macromolecular substances must be organic micromolecular free radicals which include unsaturated bonds and are in an activation state. All the “micromolecular organic free radicals” will be combined to form long-chain molecules and emit the heat once leaving the high-temperature area of cracking reaction, and then form the tar macromolecular substances again. The difference is that the tar macromolecular substances produced secondarily are reduced. For completely switching the tar macromolecular substances to the micromolecular substances in the stable state, we tried to apply the “hydrogenation catalysis cracking technology” which is universally adopted by petrochemical industry to cracking transformation of the biomass gasification tars, we hope to radically resolve the secondary pollution of the “tar” through the “hydrogenation catalysis cracking technology”, but the “hydrogenation catalysis cracking technology” needs a lots of harsh reaction conditions, such as a specific catalyst, a hydrogen source, high temperature and high pressure, so that the equipment is expense, the production technology is complicated, the safety coefficients are low, the operation is troublesome, the operation cost is high, and the economical efficiency cannot be compared with the fossil energy. Therefore, the “hydrogenation catalysis cracking technology” does not have big practical value in the high-efficiency clean conversion application of the macromolecular substances.
For example, a combustion method and a combustion device of granular fuel, Invention Patent, China, 200810056512.4, an enough and steady red-hot carbon residue layer cannot be formed; and a large part of pyrolysis gas of the granular fuel is not cracked, and directly enters a “flame combustion zone” over the red-hot carbon residue layer in a form of a tar macromolecule gaseous substance, so the secondary pollution of the smoke and tar is inevitable.
Although a low-NOx combustion device and a combustion method for biomass, Invention Patent, China, 200410098604.0 have excellent effects in the aspect of reducing NOx discharge, a large part of pyrolysis gas from a pyrolysis chamber is not cracked, and directly enters the arranged “combustion chamber” through the arranged “communication port” in the form of the tar macromolecule gaseous substance, so the secondary pollution of the smoke and tar is inevitable.
Low-tar biomass gasification method and device, Invention Patent, China, 200510043836.0 and a “three-sectional biomass gasifier”, Invention Patent, China, 200720047795.9, a part of micromolecular combustible gas after the biomass pyrolysis gas is cracked at high temperature is unsaturated organic micromolecular free radical, and the micromolecular combustible gas is not the micromolecular substances in the stable state completely; when the micromolecular combustible gas departs from the high-temperature cracking reaction zone, the micromolecular combustible gas is combined to the tar macromolecular substances again, so the tar pollution is inevitable.
A coal mother-son combustion furnace and a coal combustion method for reducing fuel coal pollutant emission, Invention Patent, China, 200610088987.2, adopt a double-furnace structure, and are high in construction cost of equipment, low in automation degree and inconvenient to operate, so the furnace and the method just can be applicable to coal combustion of the manual operation and not applicable to combustion utilization of biomass and solid organic waste with higher moisture content, or else, the smoke and tar pollution will be very serious, or even the furnace cannot normally work.
A low-oxygen high temperature air combustion method and a device thereof, Invention Patent, China, 200610032389.3, can reduce emission of the NOx and smoke to a certain extent, but the secondary pollution of the smoke and the tar is still inevitable. Above all, when the method and the device are applied to combustion utilization of the biomass and the solid organic waste, the secondary pollution of the smoke and the tar will be more serious.
An “integrated composite gasifier”, Invention Patent, China, 200910043224.X, an anoxic combustion zone is a small inverted cone space, so that content is small and easily burnt out, temperature accumulation is difficulty formed and an enough red-hot carbon residue layer is generated. Thus, a primary combustion product from the anoxic combustion zone easily forms incombustible smoke which mainly contains CO2. The pyrolysis gas from “a hearth dry distillation layer and a drying layer” cannot be subjected to catalytic cracking by the red-hot carbon residue layer while most of pyrolysis gas still directly enters an “exhaust cavity” in a form of the tar macromolecular substances, so that a great amount of macromolecular substances enters a “gas stove” together with the gas in a gaseous state, so as to inevitably generate secondary pollution of the tar. Furthermore, just the dry material can be used, if the used material is high in moisture content, the secondary pollution of the smoke and the tar is more serious, or the device cannot normally work.
An user updraft tar-free biomass gasification direct-combustion furnace, Invention Patent, China, 201010152803.0, the biomass is added from the upper part, the tar macromolecular substances in the pyrolysis gas directly enter an oxygen-enriched combustion zone without pyrolysis, so that the secondary pollution of the smoke and the tar will be inevitable. Furthermore, just the dry material can be used, if the used material is high in moisture content, the secondary pollution of the smoke and the tar is more serious, or the furnace cannot normally work.
A method for eliminating a tar wastewater of the gasifier and improving gas generation rate, Invention Patent, China, 201010134070.5, firstly, the biomass in a “gasifier cavity” is easy to form internal empty combustion because of providing of a “reaction chamber” at the center; a lot of tar macromolecular substances, incombustible carbon dioxide and water vapor are generated; the design purpose cannot be achieved just by cracking conversion of the “reaction chamber” at the center; meanwhile, a lot of smoke and tar pollution is certainly generated when the cover needs to be opened to charge; moreover, even if the “reaction chamber” at the center can completely convert the tar gas, the water vapor and the carbon dioxide into the micromolecular combustible gases under the assistance of an internal “electric heater”, most of the micromolecular combustible gases are unsaturated organic micromolecular free radicals, and combined with each other to form the tar macromolecular substances after being exported along with “a gas piping”, so as to generate the tar pollution. In addition, just the dry material can be used, if the used material is high in moisture content, the secondary pollution of the smoke and the tar will be more serious, or even the gasifier cannot normally work. Therefore, the method is a technical scheme free of any practical value.
In fact, high-efficiency clean burning method and device of a macromolecular substance, which can use the dry material, also can use the wet material, are simple in technology, low in construction cost, stable to operate, convenient to use, fast in ignition speed, small in operating cost, and free of smoke and tar pollution and safe to run and operate, do not generate the tar wastewater, and can achieve zero emission of “dioxin” in the waste incineration disposal process, have energy-efficient and environment-friendly dual effects, and also have obvious comparable economical efficiency in comparison with fossil energy, have not yet been reported in the international scope.